Unmarked escapees undermine policy and public trust in Chilean salmon aquaculture

Abstract

Fish escapes from open water net pens around the globe present persistent and unresolved challenges for aquaculture governance, environmental stewardship, and industry accountability. These escape events are widely recognized as disturbances to ecosystem services and functions [1], carry significant social and financial repercussions [2], and have prompted regional prohibitions on net-pen farming [3]. Particularly concerning is the potential for escaped fish to reproduce successfully [4], which can lead to genetic introgression with wild conspecifics or negative interactions with other native species [5] and, ultimately, the establishment of undesired, non-native populations [6]. Yet a critical barrier to effective fisheries regulations and management is the lack of certainty: Are these fish caught at sea, rivers, and lakes recent escapees, or were they born in the wild? This ambiguity obscures ecological assessments and undermines both policy enforcement and conservation planning.

Nowhere is this environmental policy gap more pressing than in southern Chile, where farming non-native Atlantic salmon (Salmo salar), coho salmon (Oncorhynchus kisutch), and rainbow trout (O. mykiss) in sea net pens has become a pillar of the national economy. Over 100 mass salmon escapes were reported in the last three decades, overlapping with a period in which various trout and salmon populations were reported to establish throughout the region. Nowadays, ecological knowledge on naturalized salmonids is blurred by the mixed presence of aquaculture-origin fish and subsistence fisheries of any salmonid banned by rules seeking to avoid theft and commercialization of farmed fish. Therefore, we argue that standardized, mandatory marking of all fish farmed in open water net pens should be a policy priority. Reliable data on the origin of wild-caught salmon is crucial for informed decision-making, ecological research, and restoring public trust in open water aquaculture in Chile.

Citation

Olivos, J. Andrés; Arismendi, Ivan; White, Seth M.; Quinn, Thomas P.; Thorstad, Eva B.; Penaluna, Brooke E.; Soto, Doris. 2026. Unmarked escapees undermine policy and public trust in Chilean salmon aquaculture. Reviews in Aquaculture. 18(1): e70105. https://doi.org/10.1111/raq.70105.